I think you have this backwards.
YOU DO NOT WANT TO DELETE THE ORIGINALS. Let me repeat that. YOU DO NOT WANT TO DELETE THE ORIGINALS.
Most people do not export every single photo and then leave them there sitting on the hard disk. Why? Because they export the photos AS NEEDED, make use of the exported photos (e-mail, web, print, other), and then when the export is no longer needed, they delete the exports (knowing that you can reproduce the exported photo EXACTLY by exporting again, assuming that you have not deleted the original).
In this way, you have only a single copy (your originals) of your photos on your primary hard disk(s) — of course, you need backups of your photos and catalog file on a different hard disk.
I understand not deleting the originals, however I am referring to the really bad originals. The garbage pics. I am getting better so am taking less but each pic is roughly 30mb each and I always have pics that are garbage. The good news is Dropbox has 1TB now for $10 a month...
If you want to delete the really bad photos, that's fine, I don't have a problem with that. Why bother exporting and editing them in that case? Just delete them immediately after import, or don't even bother importing them.
Well I suppose I've answered my own question however I really appreciate your responses. Basically what I was doing was taking the original RAW from the card and copying into a file. Previews or large thumbnails never is detailed or fast enough to quickly review the pictures to see whether I want to discard them or not, so I import them all and under Develop section delete the ones I don't like, however the command, option+delete on a Mac, only deletes them from LR, not the hard drive. So then when I export the finished edits, I'm left with a massive amount of originals that I don't want.
Just now however I discovered I could just press "x" and it flags the pic as rejected and then when I have gone through that entire roll, I can simply press command+delete and it automatically asks me if I want to delete from disk and LR the selected rejects.